"Bird Cloud" is the name that Pulitzer Prize–winner Annie Proulx gave to 640 acres of Wyoming wetlands and prairie, with 400-foot cliffs plunging down to the North Platte River; on the day she first visited, a cloud in the shape of a bird hung in the evening sky. Proulx also found abundant wildlife there, including pelicans, bald eagles, golden eagles, great blue herons, ravens, scores of bluebirds, harriers, kestrels, elk, deer and a dozen antelope. She fell in love with the land, then owned by the Nature Conservancy, and she knew what she wanted to build on it—a house in harmony with her work, essentially a library surrounded by bedrooms and a kitchen. Proulx's first work of nonfiction in more than 20 years, Bird Cloud is the story of designing and constructing that house, with its solar panels, Japanese soak tub, concrete floor and elk horn handles on kitchen cabinets. It is also an enthralling natural history and archaeology of the region—inhabited for millennia by Ute, Arapaho and Shoshone Indians—and a family history going back to 19th-century Mississippi riverboat captains and Canadian settlers.